Tape drive apparatus

Abstract

Embodiments of the present disclosure provide apparatuses and methods involving a tape drive apparatus. Briefly described, in architecture, one embodiment of a tape drive apparatus, among others, can be implemented as follows. The tape drive apparatus comprises an interface for coupling at least first and second requesters to the tape drive apparatus, the interface being adapted to receive media control requests from the requestors and identifiers of the requesters; and logic circuitry for generating log entries and writing the log entries to a log. Each log entry indicates at least a type of one of the media control requests and the identifier of the respective requestor, the logic circuitry being adapted for identification of potentially conflicting ones of the media control requests received from different ones of the at least first and second requestors. Other apparatuses and methods are also included.

1 . A tape drive apparatus comprising: 
 an interface for coupling at least first and second requestors to the tape drive apparatus, the interface being adapted to receive media control requests from the requestors and identifiers of the requestors; and    logic circuitry for generating log entries and writing the log entries to a log, each log entry indicating at least a type of one of the media control requests and the identifier of the respective requestor, the logic circuitry being adapted for identification of potentially conflicting ones of the media control requests received from different ones of the at least first and second requesters.    
     
     
         2 . The tape drive apparatus of  claim 1 , wherein the log is circular.  
     
     
         3 . The tape drive apparatus of  claim 1 , the logic circuitry being adapted to write a log entry for each of the media control requests.  
     
     
         4 . The tape drive apparatus of  claim 1 , the logic circuitry being adapted to write a log entry for a current one of the media control requests, if a previous one of the media control requests has been received from a different requestor than the current one of the media control requests.  
     
     
         5 . The tape drive apparatus of  claim 4 , the logic circuitry being adapted to read a previous log entry in order to determine if the requestors of the previous one of the media control requests and the current one of the media control requests are different.  
     
     
         6 . The tape drive apparatus of  claim 1 , further comprising a rule base, the logic circuitry being adapted to use the rule base for identification of the potentially conflicting ones of the media control requests.  
     
     
         7 . The tape drive apparatus of  claim 1 , further comprising a memory for storing a set of error patterns, each error pattern comprising at least first and second consecutive types of media control requests, the logic circuitry being adapted to use the set of error patterns for identification of potentially conflicting ones of the media control requests received from different requestors.  
     
     
         8 . The tape drive apparatus of  claim 7 , the set of error patterns having an error pattern comprising a rewind-type media control request followed by a write-type media control request.  
     
     
         9 . The tape drive apparatus of  claim 6 , the logic circuitry being adapted to read a previous log entry for the identification of the potentially conflicting ones of the media control requests.  
     
     
         10 . The tape drive apparatus of  claim 6 , the logic circuitry being adapted to generate an error signal if potentially conflicting ones of the media control requests are identified.  
     
     
         11 . The tape drive apparatus of  claim 6 , wherein the interface for receiving the media control requests is a FibreChannel compliant port and worldwide names of the requesters are used as the identifiers.  
     
     
         12 . A computer program product for controlling a tape drive, the computer program product comprising instructions for: 
 receiving media control requests from requesters coupled to the tape drive and identifiers of the requesters;    generating log entries and writing the log entries to a log of the tape drive, each log entry indicating at least a type of one of the media control requests and the identifier of the respective requestor; and    identification of potentially conflicting ones of the media control requests received from different ones of the requestors using the log entries.    
     
     
         13 . The computer program product of  claim 12 , the instructions being adapted to write a log entry for each of the media control requests.  
     
     
         14 . The computer program product of  claim 12 , the instructions being adapted to write a log entry for a current one of the media control requests, if a previous one of the media control requests has been received from a different requestor than the current one of the media control requests.  
     
     
         15 . The computer program product of  claim 14 , the instructions being adapted to read a previous log entry in order to determine if the requesters of the previous one of the media control requests and the current one of the media control requests are different.  
     
     
         16 . The computer program product of  claim 12 , the instructions being adapted to use a rule base for the identification of the potentially conflicting ones of the media control requests.  
     
     
         17 . The computer program product of  claim 12 , the instructions being adapted to use a set of error patterns for identification of potentially conflicting ones of the media control requests received from different requesters, each error pattern comprising at least first and second consecutive types of media control requests.  
     
     
         18 . The computer program product of  claim 17 , the set of error patterns having an error pattern comprising a rewind-type media control request followed by a write-type media control request.  
     
     
         19 . A method of writing log entries to a log of a tape drive apparatus, the method comprising: 
 receiving media control requests from requestors coupled to the tape drive and identifiers of the requestors;    generating log entries and writing the log entries to a log of the tape drive, each log entry indicating at least a type of one of the media control requests and the identifier of the respective requester; and    identifying potentially conflicting ones of the media control requests received from different requesters using the log entries.    
     
     
         20 . The method of  claim 19 , wherein the log entry is written to the log for each of the media control requests.  
     
     
         21 . The method of  claim 19 , wherein the log entry is written for a current one of the media control requests if a previous one of the media control requests has been received from a different requester than the current one of the media control requests.  
     
     
         22 . The method of  claim 19 , further comprising reading a previous log entry in order to determine if the requestors of a previous one of the media control requests and a current one of the media control requests are different.  
     
     
         23 . The method of  claim 19 , further comprising using a rule base for identification of the potentially conflicting ones of the media control requests.  
     
     
         24 . The method of  claim 19 , further comprising using a set of error patterns for identification of potentially conflicting ones of the media control requests received from different requestors, the set of error patterns having an error pattern comprising at least first and second consecutive types of media control requests.  
     
     
         25 . The method  claim 19 , further comprising read a previous log entry for the identification of the potentially conflicting ones of the media control requests.  
     
     
         26 . The method of  claim 19 , further comprising generating an error signal if potentially conflicting ones of the media control requests are identified.  
     
     
         27 . A computer program product for analysing a log of a tape drive, each log entry of the log indicating at least a type of one of a plurality of media control requests received from a plurality of requesters and the identifier of the respective requester, the computer program product comprising instructions for: 
 reading the log from the tape drive; and    displaying log entries for review by a user.    
     
     
         28 . The computer program product of  claim 27  operable to automatically identify potentially conflicting ones of the media control requests received from different requestors.  
     
     
         29 . A sequential storage apparatus comprising: 
 means for coupling at least first and second computers to the sequential storage apparatus, the means for coupling being adapted to receive media control requests from the computers and identifiers of the computers;    means for generating log entries and writing the log entries to a log, each log entry indicating at least a type of one of the media control requests and the identifier of the respective computer; and    means for identification of potentially conflicting ones of media control requests received from different computers using the log entries.    
     
     
         30 . The sequential storage apparatus of  claim 29 , further comprising signalling means for signalling an error to the different computers, if potentially conflicting ones of the media control requests are identified.